- Get a half-full jar of hot water
- Add as much sugar to the water
- Mix them well together
- Add food coloring and then stir them (Optional)
- Put a stick into the jar or tight a string to a stick and put it into the jar
- Wait until it forms crystals
To make rock candy, we need to add more sugar than the water can dissolve at room temperature. Because temperature affects the dissolving process. The higher the temperature is, the more solute can dissolve in the solvent. In this case, we need a greater salute so that the solvent can’t dissolve more solute, to create a saturated solution. As the saturated solution started to cool down, it becomes a supersaturated solution which the solution contains more solute than what the solvent can dissolve. A supersaturated solution is unstable and the sugar will come out of the solution to form a crystal in which a process called precipitation. The other process is called evaporation in which the water evaporates that will make the solution more saturated. When the solution becomes more and more saturated, the sugar will come out of the solution to form a crystal. We put the string or the stick to provide a surface for the crystal to form.